Differences in metered and measured oxygen concentrations during nitrous oxide analgesia.
D000698:Analgesia; D000773:Anesthesia, Obstetrical / Q000295:instrumentation; D000776:Anesthesiology / Q000295:instrumentation*; D005260:Female; D006801:Humans; D009609:Nitrous Oxide / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D011247:Pregnancy
D009609:Nitrous Oxide; D010100:Oxygen